Lathe fixture



9, 41. J. J. OVERZAT. 2,

I LATHE FIXTURE Filed March 10, 1945 2 Sheets-Sheet 1 'INVENTOR.

jjosiep/l J Overzal AfTokA/EX mm 9, 1947.. OV A 2,427,0m

I LATHEPIXTURE Filed March 10, 1945 v 2 Sheets-Sheet 2 INVENTOR. Jbsep/r J Grerzaf Patented Sept. 9; 1947 4-Glaims.

(Gfanteflfiiiidei the act of Marcli 51883, as

amendiiniirireo,

11; This invention relates .toa lathe fixture for turningeorlshapingaconcavezand -convex -surfaces.

An--object of this-invention-is to provide 8;:fiX- ture which may: bereadilyi attached toalathe to permitturning-of convex or concave surfaces of anlinfinit'e-varietyof radiit. Another object is to provide a fixture readily attachable toalathe to permit turning of convex and concave surfaces .of' identicalradiua I,

Stillanother obiectis-wto provide a readily attachable sphericalisunface turning lathefixture which mayv be-readily converted fromaturning convex surfaces-tot turningeconcave surfaces-of equalv or unequal radii and :vic versan Inthedrawingst 7 Fig. 1 is a side view in-elevationoflthe: fixture mountedon alathew V p Fig. 2' isavertica-l sectionrthrough -the fixture along-theline 2-2 inFig. l.

Fig; 31isa vertical-section alongnthe line 33- 20-pound.rest tfltkfi ym i d'p t Fig 41s atop viewof the fixturemountedlona lathe with the fixture adjusted to turn convex surfaces -of.-a desired-radius.

Fig. fi'is atop-view of ithe-fixture mountedon mounted a compound-restbase I3j-coiii1'1ouiidrest 1i swivel l4 and compound restt'op" I55 A cutting tool I6 is 'carriedin 'a tdolholdeflHand is held by the .tool post l8 against the work, illustrated as block l9, which is centeie'din-the chuck 29':

The" fixture constituting the subj ect oi'this invention may 'be "attacHedftUjth'e lathe bolting, weldingclamhih'g'or other- -suitable manner; asde'sired." Asilliistratd in the'dr'awings, lathe carriage II is provided with two 1117 ternally threaded bolt holes 2| and 22, whose center lines lie directly beneath the center line of the lathe. The compound rest top I is provided with two similar internally threaded bolt holes 23 and 24, whose center lines are in line with the longitudinal axis of the compound rest top 15.

An arm 25 is secured to the compound rest top [-5 by the machined pin-bolts 26 and 21 and a similar arm 28 is secured to the carriag H by a machined pin-bolt 29. The machined pin-bolts 26, 21, and 29 fit snugly in machined holes drilled in the arms 25 and 28 and said pin-bolts are end threaded so that they may be interchangeably screwed into the threaded bolt holes 2|, 22, 23 and 24. Embracing arms 25 and 28 in an adjustindependently monaxis 1928;.379 0. G. .757l) able relationshipqarertwolinter-related collars 39, eachaofl-whiohrisqprovideda with aspindle 31' and a setascrew 32 -(see Fig. 2)-.- The s1oiridles--31' are adaptedatoabut. each--- other; I and I are. held in alignmentbwa sl-eeve '3 8; The armt 28 is :preferably -provided-at its outerend-.witha dep din roller. '34 -forouter support-2o-fasaidtarrn, which rollerrests upona-level plate 35 suitabl$ mounted unthebedJZ: v

The aoperationeof the fixture is as followsn The ccmpoundrestswivel ll-islinitially fixed impositione so, that'the zcompound restetop I 5 may move relatively gto -it .onlyei-ni a direction-parallel to the center linewfthe lathel. The cutting. edge of the cutting tool I G ls thenlada'usted vimrelation to -.the work block! 9 so that it i fixed i to -'0pe-ra;te-' at the: horizontalnlevel of-the centerof-. the block Is; In: preparation or turning: convex surfaces, the arm 25: isathen fixedly attached-t0? the com- 2fi and 2l}whichare screwed into-boll) hole /23 and 24 -respeetive;1 y, The arml28ris-secured. tothe lathe: carriage I 'l hy a-single-machined pin-bolt 29-screwedLintothebolt holedL Thefradiusato I t I 25 be;:cut 'is theri dterminedt bys1id ing tfie assezr" bledQcoll'ars @39Z along: the arnish-25 and 2ft lokihgytl ie mlih placesatthe'pos-itio M n dy mean l fitli l eg Q}; f oa ius to=be ut is -measured-1in\ this instance fwm the centerdme sotofi pin-ebolt' 29.1 cen 111-16 ofwthmcollars 39, which i also the c dles 3w ndith'etsetse V s--3-2; Sleeve:33 -retains vspir'icllee 31 in 1&1alignmenhandabothare e to berotated about theircomgthe complound'aoross the r-otatingwvork re s inthe turning -o-fl-a desired convex sura'ce on the work-piece I9. Arm 25 is fixedly attached with relation to the compound rest top 40 I5 by the pin-bolts 26 and 21, whereas the arm 28 is free to rotate about the pin-bolt 29. The

arms .25 and 28 are free to oscillate relative to each other about the common axis of the spindles 3|. The travel of the compound rest across the 5 work l9 results in the arm 28 rotating about the pin-bolt 29 and in a reciprocative movement of the compound rest top l5 parallel to the center line of the lathe. In other words, th spindles 3| are caused to describe an are about the pinbolt 29, and the cutting tool I6 is thereby caused to describe a similar arc of the same radius across the work, the movement being translated through the medium of the fixedly attached arm 25 (see Fig. 4)

To convert the fixture to machine a concave the sleeve 33.

3 surface, it is necessary only to remove the pinbolt 21 from the bolt hole 24 and the arm 25, and insert it through the arm 28 into the bolt hole 22. This results in the arm 28 now being fixedly attached with relation to the carriage l l by the pin-bolts 29 and 21, whereas the arm 25 is now free to rotate about the pin-bolt 26 (se Fig, Movement of the compound across the work in a this case results in the arm 25 rotating about the pin-bolt 26.

The arm 25 also oscillates about the axis of spindles 3| resulting in the pin-bolt 26 describing an are about the spindles 31. The pin-bolt 26 being secured in bolt hole 23, a reciprocative V is an inherent function of the device, While the collars 30 by means of the set screws 32 permit quick and simple change of the radius of curvature to an infinite number of values. The highest value of radius of curvature which may be utilized is limited only by th length of the arms 25 and 28, which may be as long as desired. Very small radii of convex or concave curvature may be achieved by screwing the pin-bolts 26 and 29 into the bolt holes 22 and 24, and utilizing one or the other of the bolt holes 23 or 2!, as the case may be, for the arm locking pin-bolt 21. Thus,

the axis of the rotational pin-bolt is brought as close as possible'to the axis-cf the collars 30.

The fixture of this invention may be easily and V quickly afiixed to or removed from a lathe, by'

merely screwing three pin-bolts into bolt holes provided to receive them, or by removing three pin-bolts. The fixture may be made attachable by clamps or by any other suitable device, or may i ade an integral part of the lathe, as desired.

te arms 25 and 28 be long or heavy, or

9 ay be supported by-the roller 34 m at outer end of the arm 28 andridmgupon h le ate' 35; The arm 2-5 is also Supported thereby th I the spindles 3i and It is to be understood that iratrd bus modifications and changes'may be ma in t ei'ticn without departing from the spam a scope thereof as set forth in the appended- 1aim The invention described herein may be manufactured and used by or for the Government f the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is:

1. In a lathe having a carriage, a cross-slide freely, slidablymounted on the carriage, a fixture therefor for turning convex and concave surfaces comprising an arm adapted to be attached to said carriage. and an arm adapted to be attached to said cross slide, one of said arms being fixedly attached and the other being rotatably attached, and means securing said arms together and holding said arms in fixed relation but permitting oscillatory motion relative to each other about a common axis.

2. In a lathe having a carriage, a cross-slide freely, slidably mounted on the carriage, a fixture therefor for turning convex and concave surfaces comprising an arm adapted to be attached to said carriage and an arm adapted to be attached to said cross slide, one of said arms being fixedly attached and th other being rotatabl attached, and adjustable means slidably enclosing both arms to secure said arms together and hold them in fixed relation with each other but permitting oscillation relative to each other about a common axis. 7

3. In a lathe having a carriage, a cross-slide freely, slidably mounted on the carriage, a fixture therefor for turning convex surfaces comprising an arm adapted to be rotatably attached to said carriage and an arm adapted to be fixedly attached to said cross slide, and means securing said arms together and holding said arms in fixed relation but permitting oscillatory motion relative to each other about a common axis.

4. In a lathe having a carriage, a cross-slide freely, slidably mounted on the carriage, a fixture therefor for turning concave surfaces comprising an arm adapted to be fixedly attached to said carriage and an arm adapted to be rotatably attached to said cross-slide, and means securing said arms together and holding said arms in fixed relation but permitting oscillatory motion relative to each other about a common axis.

JOSEPH J; OVERZAT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 2,364,977 Hendel l; Dec. 12, 1944 

